Edit the sixteen color-value variables, and create your own syntax highlighter colorscheme.
When using Base16 Builder as a building tool, you can, like Solarized, make colorschemes that come in a light – and in a dark background version.
The Sass variables that are used here in this 'Colorscheme Lab', are basically the same that are used in the template.erb files by Base16 Builder, so after creating a colorscheme with this lab, converting to many application formats for syntax highlighting comes within reach.
A CodePen by Bram de Haan